N54 Carbon Fiber Driveshaft from the Driveshaft Shop (DSS)

Two words we hear often, sometimes after catastrophic driveline damage:

Wheel hop!

While I've considered this phenomenon mostly fixed with my rear suspension changes it is still not entirely gone and it can still be catastrophic to drivetrain parts especially those that are non hardened OEM. Addressing wheel hop is tricky on this platform partially due to independent suspension and in part due to rubber OEM bushings/mounts that are made to make the car drive smooth from the factory. I won't discuss wheel hop in this thread as there's another one dedicated to it. What I want to let you guys know about is a new driveshaft option coming from the Driveshaft Shop (DSS).

N54 community already has a great alternative to OEM rear axles with the DSS. I've had these on my car for the last 2 years, after snapping one of the OEM ones, and never looked back. The style of the axle and CV arrangement that DSS uses on the N54 rear axles has been tested to 6500lb-ft of torque which is pretty impressive.

Next up is the driveshaft and they are now equipped to produce CF driveshafts for BMWs. In terms of how this differs from the OEM one and how it compares to steel/chromoly, aluminum here's what they have to say:

Originally Posted by Driveshaft Shop

1. Steel or Chromoly tube will torsionally twist about 5-7 degrees

2. Aluminum will torsionally twist about 20 degrees

3. Carbon Fiber will Twist about 30 degrees

What happens with the different material does not stop there, when the Steel/Chromoly comes back it does it like
a spring with allot of force and power, The Aluminum also comes back quick. Not as quick as the steel but still has
that spring effect. the carbon on the other hand comes back slower and over more time. This will allow the tube to
take some of the harmful shock factor out of the drive train.

And here's some of their thoughts on wheel hop:

Originally Posted by Driveshaft Shop

i also read about wheel hop, we have been doing some work with the diameters of the axles bars. When a set of axles is the same diameter they both will twist up and release at the same rate. what happens on most cars is when they twist up and release, then do it again it causes the wheels to hop. what we have been doing it altering the shaft diameter of the axle bars so they twist and release at different rates. This allows one wheel to start to spin and will stop the hopping. This does not work on all cars but for most it has worked very well. i may try this for this platform.

The current one is being built for the LARGE pumpkin housing fitting the 6MT N54s. They're also willing to make them for the M3 platform as well but will need measurements. If anyone is interested let them know. For the automatics I don't have the specs or the car for that so anyone with a 6AT transmission if you're interested give Frank@DSS a shout.

EDIT: Updated with more pictures that may clarify some of the questions you guys had about the design of the N54 driveshaft:

No idea. Really not getting it for weight savings but for minimizing shock to drivetrain components. In case of breakage too though a CF driveshaft will just disintegrate and not go through your floor and catapult the car in the air.

If DSS can't(I'm sure they can) then you could get one from several other drive line companies. CF driveshafts have been around for a while.

Be cautioned however, CF driveshafts are EXTREMELY strong torsionally, but when it comes to impacts they are very weak. Which means wheel hop is a very dicey proposition. I'm not sure if the M3s have the same wheel hop problem we have.

Be cautioned however, CF driveshafts are EXTREMELY strong torsionally, but when it comes to impacts they are very weak. Which means wheel hop is a very dicey proposition. I'm not sure if the M3s have the same wheel hop problem we have.

They definitely make a nice CF shaft, the one going into my drag car will be from DSS. Like someone said though they are strong in some ways and not so much in others and ive seen a few break easier than an aluminum one. It is MUCH safer though than any metal one.

Carbon fiber driveshafts are great for high horsepower/torque applications becuase they can handle torsional(twisting) forces VERY well and are EXTREMELY lightweight. However when you wheel hop it has a hammering effect from the rapid loading and unloading of the torque and the CF just can't cope.

Think of it like this: if you just set weight on a cinderblock it can support a huge amount. However, if you smack it with a small hammer it will break apart very easily.

Carbon fiber driveshafts are great for high horsepower/torque applications becuase they can handle torsional(twisting) forces VERY well and are EXTREMELY lightweight. However when you wheel hop it has a hammering effect from the rapid loading and unloading of the torque and the CF just can't cope.

Think of it like this: if you just set weight on a cinderblock it can support a huge amount. However, if you smack it with a small hammer it will break apart very easily.

Gotcha but if you eliminate the wheelhop issues wouldn't you want this then?

Carbon fiber driveshafts are great for high horsepower/torque applications becuase they can handle torsional(twisting) forces VERY well and are EXTREMELY lightweight. However when you wheel hop it has a hammering effect from the rapid loading and unloading of the torque and the CF just can't cope.

Think of it like this: if you just set weight on a cinderblock it can support a huge amount. However, if you smack it with a small hammer it will break apart very easily.

this.

If you are having wheel hop, chances are good that you break your cf driveshaft easier than aluminum driveshaft. Vic Taza broke his cf driveshaft because of the very same reason when he did a burnout with slick tires, something that hadn't happened to the stock aluminum driveshaft.